Lifting-magnet.



A. 0. EASTWOOD.

LIFTING MAGNET. APPLIUATION FILED AUG. 10', 1908.

928,51 0. Patented July 20, 1909.

2 SHEETS-SHEET 1.

AT ORN EY A. U. EASTWOOD.

- LIF'FING. MAGNET. APPLIOATION FILED AUG. 10, 1908.

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OF CLEVELAND, OHIO.

LIFTING-MAGN ET.

Specification of Letters Patent.

Patented July 20, 1909.

Application filed August 10, 1908. Serial No. 447,682.

To all whom it may concern:

Be it known that I, ARTHUR C. EASTWOOD, a citizen of the United States,residing at Cleveland, in the county of Cuyahoga and State of Ohio, haveinvented or discovered new and useful Improvements in Liftin Magnets,-of which the following is a speci :ation.

My invention relates to new and useful improvements in lifting magnets.

The objects of my invention are to'provide means whereby the magnetizingwinding of the magnet may be more expeditiously and cheaply wound;whereby the assembled winding may be more readily and safely handled;and whereb when in place in the magnet case, the wint ing will besupported and protected in such a manner as to guard against the effectsof the rough handling and exposure, to whichthc magnet will be subjectedin service.

My invention applies particularly to lifting magnets in which thewinding is of the so-called strap or ribbon form, that is, theconducting member of the winding is rectangular in cross section havinga width considerably greater than its thickness. Certain features of myinvention are, however, equally applicable to magnets in which thewinding is made up of the ordinary forms of insulated wire. In a strapor ribbon winding it is desirable to form the winding of a number ofcoils, one above the other rather than of a. single coil of greaterdepth. This is true because insulatin material, such as asbestos, in theform (it a ribbon must be in the neighborhood of 10/1000 ofaninch inthickness to be commercially racticable. In order that the insulatingribbon may form a minimum proportion of the total winding space, it isnecessary that the conducting ribbon be as thick as )ossible comparedwith the thickness of the insulating ribbon. With a conductor of givencross section, if the thickness is made large, the width In ust be madecorrespondingly smaller. Naturally a coil of large diameter wound u ofnarrow ribbons of copper and asbestos is very delicate and dillicult tohandle, since it is very likely to dish out of shape by the slipping ofone turn over another, which is very likely to ruin the coil, becausethe insulating ribbon may become torn or displaced so as to permitneighboring conducting turns to come into electrical contact thusestablishing short circuits.

My invention provides means whereby'the several shallow coils which makeup the winding are well supported during the process of winding and thesubsequent handling of the coil prior to securing it within the frame ofthe lifting magnet.

My invention provides simple and reliable means for clamping the windingfirmly in place soas to prevent it from either moving vertically orturning about its axis.

Referring to the accom nmying d 'awings, Figure 1 is a top plan vlew;Fig. 2, a side elevation partly in section of the winding of my improvedmagnet and the means for supporting the'winding; Fig. 3, a sideelevation partly in section of a complete magnet; and Fig. 4, a bottomplan View of a portion of the magnet case with the winding andbottom-plates removed.

In these figures, A is an annular bottom plate preferably of brass,having its inner and outer peripheries provided with finished flanges aand (1 which are provided with screw holes a spaced closely together sothat the bottom plate may form a water tight joint with finishedshoulders on the lower face of the central core B and the outer pole Oof the magnet case. The plate A is also provided with an upwardlyprojecting flange a which serves as a mandrel upon which the coilsarcwound.

I have shown four separate coils e, 6 e and c. In windin the coils theform or mandrel comprised y the bottom plate A with its flange a isfirst thoroughly insulated by means of the insulating plate a and theinsulating sleeve a." which slips over, or may be wound upon, the flangea. The form may then be mounted upon a rotatable head stock, preferablyso arranged that the plate A will be horizontal thereby bettersupporting the insulation and the coils in the process of winding. Thefirst coil is then wound, being made up of alternate strips or ribbonsof copper and insulation, such as asbestos. When the first coil iscompletelywound, its periphery is held by suitable clamps or bindingwires (not shown). The insulating plate a is placed above the coil e andthe secondcoil'c is similarly wound. The remaining coils c and e arealso wound in a similar manner. Suitable connections, of course, beingmade between the end of one coil and the beginning' of the next so as tocause current to flow through the several coils-in series in a uniformdirection. When the last coil e is wound a heavy insulating plate islaid upon it, this plate being provided with s ots through which passthe terminal connections a". Radial clamping straps s, s s and s arethen placed over this top plate of insulation and are drawn down bymeans of bolts or screws d and (1 respectively, the screws 2' engagingwith bosses at the upper end of the central flange a and the bolts dpassing through suitable ,holes near the outer edge of the oottom plateA. The bodies of the bolts d are covered with'sleeves ofinsulatingmaterial d to' prevent the possible contact with the periphery of thewinding. By means of these clamps the entire winding is clamped firmlyagainst the bottom plate A before being handled, and the entire winding,therefore, becomes a unit held firmly together and may be moved aboutand assembled in the magnet case without danger of injury to the coils.After the winding is completed, an insulating layer a is bound aroundthe exterior of the winding. The winding .is then preferably impregnatedwith a compound which will thoroughly Waterproof it. It is thenassembled in the magnet case, the inner and outer flanges of the plate Abeing firmly screwed in'place to the lower faces of the inner and outerpoles, as previously described.

As will be seen in Fig. 4, the inner and outer walls of the magnet caseare provided with slots or notches s and s respectively to accommodatethe ends of the straps s, 8 s, and s and the clamping screws and boltsId and (Z which engage the ends of these straps. The upper surface ofthe winding space is likewise provided with grooves or slots 8, 8 etc.,for accommodating the bodies of the straps s, 8 s and 8, these grooveshavin greater depth for accommodating the heads of the bolts 03 anddThis construction is adopted to secure minimum Wei ht of the completedmagnet and also to ad to the efficiency of d1ssipating the heatdeveloped within the magnetizing winding.

If the windin space were made large enough all around to accommodate theprojecting ends of the clamping straps s, '8 s, and s and deep enough toreceive the depth of the straps in addition to the depth of the Winding,the magnet would necessarily be considerably larger and heavier than amagnet in which my preferred construction 15 used; or, if the windingspace bemade of the same general dimensions, the portion of the windmgspace actually filled by the winding would be smaller, and less magnetizing force could be developed in the magnet. Further, the spacesbetween the surfaces of the winding and the magnet case would beincreased thus interfering with the conduction of heat to the magnetcase, from at their ends pockets of which the heat is finallydissipated. The outer or wearing plate D, which I preferably make ofmanganese steel is then put in lace, and the pole shoe 0 is bolted tothe ower face of the outer pole C. This pole shoe has a shoulder or step0 which engages with the periphery of the wearing plate D so as tosupport and assist in clamping the plate D in place. The pole shoe 0 isheld in place by a series of bolts or studs 0 which have their nuts andthreaded ends disposed between the ribs c whereby they are protectedfrom abrasion. The center pole shoe 6' is then bolted in lace on theface of the central pole B. This pole shoe is provided with a shoulderor step b which engages and supports the central edge of the wearingplate D. The pole shoe 1) is held in place by studs or bolts 5 whichpass through the core B, which is provided with a central opening 6*serving as a ventilating flue or duct through the magnet. The terminals6 are then connected to the lower ends of studs g carried by aninsulating plate These studs terminate in L-shaped plugs adapted toengage with removable female members g, which in turn are surroundedwith insulating sleeves each having a central passage through whichpasses a flexible connecting wire g, connecting the s:-

windings of the magnetwith a source of current. After the terminals eare connected to the stnds'y and before the insulating plate 9 isscrewed in place, the casing of the magnet is poured full of a sealingcompound A: composed of an insulating material which softens under theinfluence of heat. The spaces between the surface of the winding and theframe of the magnet. are completely filled with insulating material .inthis way. The insulating plate is then screwed in place, a gasket gbeing placed beneath it so as to form a Water-tight joint. Tl" top ofthe cavity in which the terminals are located is then closed by a steelplate 9 under which is placed packing g to effect a water-tight joint.

The walls L of the terminal spaces are preferably made very heavy andare cast inte gral with the frame of the magnet so that the terminalsmaybe protected from the hard usage to which the completed magnet willnecessarily be subjected when dangling from the end of a hoisting chainon a crane. The walls of the terminal cavity are also preferably broughtup to a sufiicient height to cover and protect the heads of the studs orscrews g, which clamp the cover plate. g in place. These upwardlyextending walls I are provided with a ertures g to prevent Wateraccumulating mtho top of the terminal cavity above the plate 9".

It is noted that I have shown the pole shoe 0' of such dimensions thatits active face will be lower than the active face of the central poleshoe 7). This is done so that the poles of the magnet may come intobetter engagement with the uneven surface of bulk material, such as pigiron. The depth of the pole ring (1 is also of advantage mechanicallysince the ring will be very strong in a vertical direction and thereforecapable of withstanding the heavy blows which it receives when thecompleted magnet, which may readily weigh 5000 pounds, is dropped uponpiles of iron and steel.

I claim 1. A lifting magnet frame having an annular space, a winding, acylindrical internal support for the winding, a cap plate for theinternal support, and means for sec u'ing the said support in the saidannular space.

2. A lifting magnet having a winding, a winding support comprising abottom plate, having a concentric shoulder 'extendin therefrom andserving as a support for sai winding, and means for clampin said windingfirmly against said bottom p ate.

3. A lifting magnet having a top plate, a central core dependingtherefrom, an outer pole concentric with and s aced from said centralcore,a winding in t e space between said central core and said outerpole, a bottom plate arranged to support the winding and having acentral flange secured to the lower face of said central pole, an outerflange secured to the lower face of said outer pole, and an upwardlyprojecting flange serving as a central support for sald windmg.

4. A lifting magnet having an annular winding space, a winding therein,a winding support comprising an annular bottom plate having annularinner and outerflanges engaging with the lower faces of the inner andouter walls of said winding space, and an upwardly projectin flangeserving as a central sup ort for sai winding.

A ifting magnet having an annular winding space, a winding therein,means for supportin and clam ing said winding in place, said means incudin a bottom plate having inner and outer flanges engaging with thefaces of the inner and outer walls of said winding space, an upwardlyprojecting flange serving as a central su port for the winding, clampingmeans zliove the winding, screws or bolts for drawing said clampingmeans toward said bottom plate and clamping, the winding between theclamping means and the bottom plate, there being pockets in the walls ofsaid winding space for accommodating said straps and said bolts orscrews.

(3. A lifting magnet having an annular winding space, a winding therein,means for supporting and clam ing said winding in ilace, said means incudmg a bottom plate having inner and outer i anges engaging with thefaces of the inner and outer walls of said winding space, an upwardlyprojecting flange serving as a central support for the winding, clampingmeans a ove the winding, and screws or bolts for drawing said clampingmeans toward said bottom plate and clamping the winding between theclamping means and the bot-tom plate.

7. A lifting magnet having an annular winding space, a, winding therein,a bottom plate having inner and outer flanges clamped .to the lowerfaces of the inner and outer walls of said windin space,vand meansindependent of the walls of the windin space for clamping said windingagainst t e upper side of said bottom plate.

8. A lifting magnet frame having an annular windin r space, and aninsertlble unit for said win ing space consisting of abottom plate, acentral support, a winding composed of a plurality of coils wound oneabove the other around the central support and rigidly clamped to thebottom late extending radially outward from sai central support, saidbottom plate having shoulders adapted to engage with the inner and outerwalls of said winding space.

9. A lifting magnet havin an annular coil space, a magnetizing coi insaid coil space, a spool upon which the coil is wound, the lower head ofsaid spool engaging with the walls of the magnet near the 0 en end ofthe annular winding space ail being adapted to make a water tlght jointthere- With'.

10. A lifting magnet having anannular winding s ace and a unit for saidwinding space sai for closing said win ing space and a windlIig clampedto the upper side of said bottom ate.

11. A lifting magnet having an annular winding space, a bottom plate,the inner and outer edges of which are screwed to the lower faces of theinner and outer walls of said windin space, a magnetizing windlng insaid Win ing space, means for clamping said winding against the upperside of sa bottom late, a cover plate of non-magnetlc materialcovering-said bottom plate, and

ole shoes clamped to the lower faces of the inner and outer walls ofsaid winding space, said pole shoes being adapted to clamp said coverplate in place. 0

12. A lifting magnet having a wlndmg space, a magnetizing winding insaid space a non-magnetic bottom plate for closlng sa1 unit eomrising abottom plate winding space, means independent of the said winding, andmeans independent of the walls of said'winding space for clamping saidWinding to said support, there being recesses in the Walls of saidwinding space for accommodating said clamping means.

14. A lifting magnet having a central ipole, an outer pole concentricwith and surrounding said central pole and removable pole shoes on thebottom faces-of both of 0 said poles, the pole shoe on the outer polebeing deeper than the pole shoe on the central pole, such that its underface is lower than the under face of the'pole shoe on the central pole.

Signed at Cleveland, Ohio, this 1st day of Aug. 1908.

ARTHUR C. EASTWOOD. Witnesses i C. PIRTLE, H. M. DIEMER.

